Quiz Bowl Buzzers

Spring 2012 - Matt Robertson

Background

I played Quiz Bowl (Scholars' Bowl) in High School and always wanted to figure out
how to build my own set of competition buzzers. This set of buzzers is comparable
to those used in schools!

Manner of Operation

This set of buzzers is designed around a PIC18 microcontroller. 10 push buttons (on
long cables) are used on the microcontroller's input pins. 10 LEDs and 1 speaker
are used on the microcontroller's output pins. The whole circuit was powered using
a wall power adapter and a 5-volt regulator.

The microcontroller is programmed to watch for a contestant to press a push button.
Once it detects a button push, it lights up that contestant's light and a sound is
output from the small speaker. Since contestants are on two teams, the speaker emits
a different tone depending on what team buzzes in. The microcontroller then ignores
all other contestants until the reset button is pressed.